Matched betting calculator
Matched betting backs an outcome at a bookmaker and lays the same outcome at an exchange, so every result pays the same. A qualifying bet usually costs a little; a free bet turns into cash. A 10 free bet at 6.0, laid at 6.2, locks in 79.3% of its value; at 2.0 it keeps only 47.1%.
The three calculations
- Qualifying bet (your cash stake B at back odds b, lay odds l, commission c): lay stake = B × b ÷ (l − c). Both outcomes then give the same result, normally a small loss: 4.5% of the stake at 3.0 laid at 3.1 with 2% commission.
- Free bet, stake not returned (value F): lay stake = F × (b − 1) ÷ (l − c). You only ever win the profit part, so longer odds keep more: even with no gap between back and lay odds and no commission, a free bet at 2.0 keeps at most 50%, at 4.0 75% and at 8.0 87.5%.
- Free bet, stake returned: lay stake = F × b ÷ (l − c), and it keeps 95.5% at 3.0 laid at 3.1.
What can go wrong
- The lay bet must be matched at the odds you entered. If the price moves before it is matched, the outcomes are no longer equal.
- The liability, what you pay out if the backed outcome wins, must be in your exchange account: here it is shown for every calculation.
- Bookmakers set their own terms for free bets (minimum odds, expiry, eligible markets) and may limit accounts. Read them first.
- A typing error in a stake is the most common way to lose money. Check both bets before you place them.
For a plain lay bet see the lay bet calculator; for the bookmaker's margin on the back odds, the margin calculator. Rules and taxes on betting differ between countries.
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